National Geographic’s worthy “Explorer” series kicks off its new season with a two-parter and a new host, Boyd Matson, who’s in Africa talking self-consciously with wildlife photographers Dereck and Beverly Joubert and, with Beverly, gingerly but determinedly sloshing through hippo dung. The 10th season’s off with a roar.

The two-part opener centers on the Jouberts’ extraordinary “Lions of Darkness ,” about cats in the Savuti region of Botswana’s Chobe National Park.

An aging emperor is chased off by three lusty young males taking over the territory and the females. The Jouberts, gradually acclimatizing the animals to floodlights, use image-intensifying equipment for filming the lions in darkness when they’re mating, hunting prey and devouring their kill.

One lioness bears a litter of three, and the narrative focuses on the surviving, plucky cub Tau, who’s left to cope alone.

His adventures continue in part two as he faces dangers while seeking his relatives. The plight of the old lion king, the growing cubs learning their lessons — an attack on a zebra is particularly grim — and Tau’s attempts to find his place in life dramatize the lions’ rough life over a three-year period.

Lacking continuity and consequence, it shows wildlife photog Nichols, who mugs a lot on camera, vaguely explaining elaborate methods of setting up shots for catching animals, but the results here don’t merit the efforts.

Brier graphically describes how the dead were mummified those many years ago as he, in turn, goes at it on camera on a corpse with a medical friend at the U. of Maryland Medical School in Baltimore. Some may find the remarkable seg grisly; others will be spellbound.

Program concludes with a sparkling performance of “Agolu,” a salutary tune about the Earth by scintillating Benin native singer Angelique Kidjo.

On-air promos hyperbolically describe the Explorer series as the “last great adventure of the weekend.” Two strong segs out of three and a gratifying kicker may not be great adventure, but they’re impressive.